The açaí seeds are an abundant byproduct of the chain of açaí and represent a significant source of lignocellulosic material for bioethanol production in the northern region of Brazil. In the present paper seeds of açaí were hydrothermally treated to overcome biomass recalcitrance for enzymatic hydrolysis. The effect of the hydrothermal pretreatment carried out with high solid loadings in the rates of sugars released was evaluated by subsequent enzymatic hydrolysis. The pretreatment used acid concentrations ranging from (0.5-1.5 %), solids loadings from 5 to 15 % (w/v) and time from 30 to 90 min at 120 °C under a pressure of 1.7 MPa. The enzymatic hydrolysis was carried out at a solid loading of 10 % DM. Hydrolysis was performed at 52 °C and pH 5.0 with an enzyme loading of 30 FPU of celullase and 50 CBU of ß- glycosidase for 72 h. The results showed that hydrothermal treatment can remove significantly hemicelluloses from seeds of açaí (80 %) and improve of yield monosaccharides released by hydrolysis enzymatic. Pre-treatment with 1.5 % sulphuric acid and 5 % solid content for 90 min at 120 °C was found to be the best condition for pre-treatment and conversion.